Can myocardial work indices contribute to the exploration of patients with cardiac amyloidosis?

Abstract

Identifying poor prognosis is essential to ensure appropriate care among patients with cardiac amyloidosis (CA). Left ventricular ejection fraction (LVEF) may remain preserved even in advanced stages. Myocardial contraction fraction (MCF) and global longitudinal strain (GLS) have been shown to be superior to LVEF in predicting survival. Non-invasive myocardial work (MW) is emerging as a new tool integrating deformation and afterload. To explore relationship between MW indices and clinical and biochemical markers; and to compare their prognostic impact with LVEF, GLS, and MCF in a population of patients with CA. Biological parameters, transthoracic echocardiography and cardiopulmonary exercise were retrospectively analysed in 118 patients with CA. Global work index (GWI) was calculated as the area of left ventricular pressure-strain loop (product of strain × systolic blood pressure). Global work efficiency (GWE) was defined as percentage ratio of constructive work to sum of constructive and wasted works. GWI and GWE were correlated with NT-proBNP ( r = −.477 and r = −.383, respectively, P < .001). GWI was correlated with peak oxygen consumption ( r = 359, P < .05). GWE was better than MCF and LVEF, and GWI was better than MCF to predict mortality. In contrast, MW indices did not add value over GLS. In CA population, MW indices are well correlated with known prognosis markers and are better than LVEF and MCF in predicting mortality.